Clang 3.1 Release Notes

Introduction

This document contains the release notes for the Clang C/C++/Objective-C
frontend, part of the LLVM Compiler Infrastructure, release 3.1. Here we
describe the status of Clang in some detail, including major improvements from
the previous release and new feature work. For the general LLVM release notes,
see the LLVM
documentation. All LLVM releases may be downloaded from the
LLVM releases web site.

For more information about Clang or LLVM, including information about the
latest release, please check out the main please see the
Clang Web Site or the
LLVM Web Site.

Note that if you are reading this file from a Subversion checkout or the main
Clang web page, this document applies to the next release, not the
current one. To see the release notes for a specific release, please see the
releases page.

What's New in Clang 3.1?

Some of the major new features and improvements to Clang are listed here.
Generic improvements to Clang as a whole or two its underlying infrastructure
are described first, followed by language-specific sections with improvements to
Clang's support for those languages.

C Language Changes in Clang

C11 Feature Support

Clang 3.1 adds support for anonymous structs and anonymous unions, added in
the latest ISO C standard. Use -std=c11 or -std=gnu11
to enable support for the new language standard. The new C11 features are
backwards-compatible and are available as an extension in all language
modes.

All warning and language selection flags which previously accepted
c1x have been updated to accept c11. The old
c1x forms have been removed.

C++ Language Changes in Clang

C++11 Feature Support

Clang 3.1 supports
most of the language
features added in the latest ISO C++ standard,
C++ 2011.
Use -std=c++11 or -std=gnu++11 to enable support for
these features. In addition to the features supported by Clang 3.0, the
following are now considered to be of production quality:

Generalized constant expressions

Lambda expressions

Generalized initializers

Unrestricted unions

User-defined literals

Forward-declared enumerations

Atomics (both libc++'s and libstdc++4.7's <atomic> are
supported)

Objective-C Language Changes in Clang

Clang 3.1 introduces several new Objective-C language features and improvements.

Objective-C literals and subscripting

Objective-C now provides additional literal expressions, including numeric, array, and dictionary literals. Additionally, array and dictionary elements can be accesses via the subscripting operator. For more information about the new literals, see the documentation for Objective-C literals and subscripting.

Format string checking for NSString literals

-Wformat now checks @"NSString literals".

Python Binding Changes

The following methods have been added:

SourceLocation.from_position (static)

SourceLocation.__eq__ and SourceLocation.__ne__

SourceRange.__eq__ and SourceRange.__ne__

Diagnostic.category_number (property)

Diagnostic.category_name (property)

Diagnostic.option (property)

Diagnostic.disable_option (property)

CursorKind.is_translation_unit

CursorKind.is_preprocessing

CursorKind.is_unexposed

Cursor.from_location (static)

Cursor.underlying_typedef_type (property)

Cursor.enum_type (property)

Cursor.objc_type_encoding (property)

Cursor.hash

TypeKind.spelling

Type.argument_types

Type.element_type (property)

Type.element_count (property)

Type.is_function_variadic

Type.is_pod

Type.get_array_element_type

Type.get_array_size

Type.__eq__ and Type.__ne__

File.from_name (static)

File.__str__ and File.__repr__

Additional Information

A wide variety of additional information is available on the
Clang web page. The web page contains
versions of the API documentation which are up-to-date with the Subversion
version of the source code. You can access versions of these documents specific
to this release by going into the "clang/doc/" directory in the Clang
tree.

If you have any questions or comments about Clang, please feel free to
contact us via the
mailing list.